1. Field of the Invention
The present invention relates to the transfer of a load to or from the cargo space of a vehicle and particularly to facilitating the placement of a wheelchair in a storage compartment of a passenger vehicle. More specifically, this invention is directed to a manually operable, gravity assisted lift device for use in the loading of a foldable wheelchair or other load into the storage compartment of an automobile, the apparatus also enabling the extraction of such a load from the vehicle storage area and the placement thereof on the ground. Accordingly, the general objects of the present invention are to provide novel and improved methods and apparatus of such character.
2. Description of the Prior Art
While not limited thereto in its utility, the present invention has been designed for, and found to be particularly useful in, the manipulation of foldable wheelchairs, whereby such chairs may be easily retrieved from and returned to a storage compartment in an unmodified conventional passenger vehicle. The first folding X-frame wheelchair was introduced in the late 1930's and is disclosed in U.S. Pat. No. 2,095,411. The development of such foldable wheelchairs constituted a major step toward allowing nonambulatory disabled persons to travel by taking their wheelchairs with them in personal automobiles. Folding X-frame wheelchairs are today in widespread use. Importing foldability to a wheelchair, however, did little to reduce weight. Further, even when folded, wheelchairs are relatively difficult to load into the storage compartment of a passenger vehicle, the storage area of a "hatchback" body style automobile or station wagon for example, because of their weight and because their dimensions render the chairs awkward to handle.
There has been a long standing need for a lifting device, characterized by ease of both installation and use, suitable for transferring a folded wheelchair into and out of a motor vehicle storage compartment. Ease of installation of such a device dictates that major modification of the vehicle not be required. Ease of use dictates, in addition to not requiring unusual effort on the part of the user that the lifting device be capable of remaining in position in the vehicle rather than having to be partially or totally installed and dismantled on each occasion of use. Further requirements of a wheelchair lifting device include reliability, adjustability to accommodate vehicles of different size and body style and modest cost. Yet another requirement for a commercially acceptable wheelchair lift is that it occupy the minimum possible space in the vehicle storage area when not in use.
Previously proposed and available wheelchair lifting devices have been characterized by an inability to fulfill one or more of the above-outlined requirements. For example, various crane-like mechanisms have been proposed for hoisting a wheelchair into a vehicle storage compartment. Such hoisting systems are awkward to use and, in most cases, must be assembled for each use and then disassembled in order to be placed into the vehicle. As an alternative to these crane-like mechanisms, wheelchair carriers have been available which have been mountable on or from a vehicle bumper. A major problem with such carriers, however, has been that they store the wheelchair to the exterior of the vehicle and thus require a cover for protection of the chair. Such covers, regardless of how well designed, deteriorate by exposure to the elements and the user incurs the expense of periodic cover replacement if, in fact, replacement covers remain available.